Immediately outside a conducting sphere (i. e. on the surface) of unknown charge Q and radius R the electric potential is 190 V, and 10.0 cm further from the sphere, the potential is 140 V. What is the magnitude of the charge Q on the sphere

Q = 5.9 nC (Approx)

Explanation:

Given:

Further distance = 10 cm

Electric potential (V) = 190 v

Potential difference (V1) = 140 v

Find:

Magnitude of the charge Q

Computation:

V = KQ / r

190 = KQ / r ... Eq1

V1 = KQ / (r+10)

140 = KQ / (r+10) ... Eq2

From Eq2 and Eq1

r = 28 cm = 0.28 m

So,

190 = KQ / r

190 = (9*10⁹) (Q) / 0.28

53.2 = (9*10⁹) (Q)

5.9111 = (10⁹) (Q)

Q = 5.9 nC (Approx)